Discussion: Power limit on stock NT fuel system

[mhuffman]

I am surprised there is such limited posting in this NT section. The 4G63 NT has a hugely flowing head and a large throttle body from the factory; i figure it is just a set of cams/springs and some intake/exhaust work away from being a very strong setup.

Being a mass airflow controlled motor, freeing up the breathing should (up to a point) be fully accounted for without requiring a re-tune, correct? adding intake/header/exhaust/cams will mean more air comes in, but this increased flow should be fully measured and accounted for and the computer will automatically add the required fuel (up to the limits of the stock fuel system).

SO MY QUESTION BECOMES: What is the maximum power that the stock 1g NT fuel system can handle, taking into account factory MAS/FP/injectors/FPR/tune? This data should be able to be obtained by monitoring injector duty cycle on a stock 1g NT engine and then looking at the % headroom.

For example, if the max injector duty cycle on a stock 1g NT is 65% (random value chosen), you have 15% headroom to stay below 80%. This means you could add up to 15% horsepower (15% of 135 would be 20 HP) before you would need to upgrade your fuel system.

 

[e85_4g63]

The problem with the non turbo 4g63 entirely is that there is a turbo version. If they're were factory B16's turbo from Honda, you'd see the same trend the 4g63's follow. No reason to beat a dead horse, if you know what I mean. Same with the SRT's. If there were AWD srt4's (neon based) there would be hardly any fast FWD's just like with the DSM's.

I know my reply is off topic a little, but it would be very simple to use an online calculator to figure out what HP the stock injectors could support at ~95% duty cycle (on race fuel, since race "gas" is going to net the most power per injector size). That's your answer.

 

[mhuffman]

my car is going to be used for rallycrossing and daily driving. I've had both a turbo dsm and an srt4. my reasons for staying N/A:

Better "balance"
more reliable
Cheaper
less complexity
Better throttle response
Lighter weight
Better handling
less cooling demand
Better gas mileage on street

I will look for injector calculators.

 

[e85_4g63]

Here ya go..

http://www.rceng.com/technical.aspx?UserID=18970959&SessionID=vbz{BymC35RSpTRCil1T

For some reason it's not working, but if you copy and paste the link above, it goes to RC engineering's injector calculator.